Telephone and telegraph circuits



'Mgrch 4, 1 930. J. w. COOK TELEPHONE AND TELEGRAPH CIRCUITS Filed April 1925 2 Sheets-She's! 1 m 16 j g/ $011+ [75 March 4, 1930.-

J. W. CCOK TELEPHONE AND TELEGRAPH CIRCUITS Filed April 8, 192,5

2 Sheets-Sheet 2 Patented Mar. 4, 1930 PATENT OFFICE JOHN W. COOK, OF TOPEKA, KANSAS TELEPHONE AND TELEGRAPH omcurrs- Application filed April 8,

My invention relates to multiplex telegraph and telephone circuits or apparatus for transmitting and receiving telephone or telegraph messages or signals over two untransposed or two transposed telegraph vwires, either one of which may be iron or copper,

' or both copper, or both iron, without interfering with existing circuits, which may be printer, duplex or quadruplex telegraph circuits.

One object of my invention consists in providing a circuit or apparatusv whereby use may be made ofexisting telephone lines, whether metallic orgrounded,-or of power transmission lines,for transmitting and receiving telephone messages or for telegraph transmission without interfering with the existing circuits.

A further object of my invention is to provide apparatus or acircuit whereby transmission and reception of telephone or telegraph messages is possible either over a telephone'metallic line as one side of a pair while employing a printer, duplex or quadruplex telegraph wire as the other side of the pair; or over a combination of telegraph and telephone Wires, without interfering with the existing circuits.

Another object of my invention consists in providing a circuit or apparatus adapted to balance out such interference in the receivin'g'apparatus as would ordinarily be experienced from ten or more quadruplex sets being operated on the same table with the receiving apparatus.

vThe foregoing enumerated objects and advantages of my invention, as well as other advantages inherent in the invention, will. all be more fully understood andv comprehended from the following detailed description of the accompanying drawings, wherein the circuits and apparatus are diagrammatically illustrated. i i p p t Figure 1 isa diagram showing a telegraph anda telephonecircuit embodying my invention.

Figure 2 is a diagram showing the combination of a telegraph and telephone circuit and atelegraph'circuit. Figure?) is a diagram illustrating my in- 1925. Serial No. 21,486.

forming the two sides of a metallic circuit for my apparatus. F igure 4: is a diagram illustrating my invention as merely applied to a telegraph wire.

Figure 5 is a diagram illustrating two transmitting and two receiving sets of my apparatus connected at each end of two telegraph wires.

In the exemplifications of the invention as shown in the drawings, beginning with Figure 1, 10 represents a telegraph wire, in quadruplex service, provided with air choke coils at 11, 11, leading to the telegraph apparatus indicated at 12, 12. 13 represents a metallic telephone simplexed circuit, which is provided with the simplex coils 1 1, 1 1, 14,

-14; a-number of fixed condensers arranged in pairs as shown at 15; selectors and telephone bridges across the lines 13, as shown at 16, and telegraph apparatus indicated at the ends of the lines and beyond the simplex coils 14, as shown at 12. The small capacity condensers shown at 151 are connected at an intermediate point, by lines 17, asa tap for the highfrequency transmitting and receiving apparatus which are schematically indicated at 18, 18; the apparatus being also shown connected with the single telegraph wire 10 by means of wires 19, 19. The condensers referred to are of such capacity as not to interfere with telephone transmission on existing lines; while the connections to the high frequency transmitting and receiving apparatus 18, 18,'which are balanced to both ratus of the multiplex circuit caused by the changing long and short ends of the quadruplex battery.

telegraph circ'uit,adapted to send and receive telephone messages or for telegraph transmlssion over a telephone metallic line as one side of a pair, while using either a printer, duplex or quadruplex telegraph wire as the other side of the pair of lines; or to be employed as a combination of telegraph ceiving apparatus 18.

and telephone wires without interfering with existing circuits,-the circuit comprises ate'legraph wire 10, in quadruplex service, provided with the air choke coils 11, 11,1eadingto the telegraph instruments or apparatus indicated at 12, 12. One end of'line 10 is shown connected to the high frequency transmitting and receivingapparatus 18, while the other end is shown connected with the adj acent high frequency transmitting and receiving apparatus 18 by the wire 20. The line 10 constitutes one side of the circuit; -while 21 represents a single Morse service; and 13 represents a metallic telephone, circuit indispatchers service. The lines '13 and 21, connected at their terminals,constitute the other side of the circuit. The telephone wires 13are provided with the simplex coils 14 to which the telegraph apparatus 12 'are connected; and the telephone line lS 'Sl10W-I1 provided at 16 with selectors and telephone bridges across the lines; and also with fixed condensers 15. The smallcapaoity condensers 15 at one end of the telephone lines are connected at an intermediate point by means of wire 22 with telegraphline 21 and with an air choke coil 11 which in turn is connected witha telegraph apparatus 12. a

The other end of telegraphline 21 is connected with a wire 23 which, at one end, is provided with an air choke coil 11 and is connected to a telegraph apparatus 12; while the other end of wire 23 is connected-with the high frequency transmitting and receiv- InFigureB I show a diagra'niiof high frequencytra-nsmitting and receiving apparatus shown at 18, connectedto two untransposed lines :in'telegraph service and 1 comprising vthe wires 24, 25, 26 and 27 in quadruplex telegraph service between two terminals; theft-wo I Wi'res Q iand Q5 being connected :at their ad "j acent ends through a' small fi xed condenser 28; while the two-wires 26 and'27 areconnected at their adjacent endsfthrough ?the small "fixedcondenser'29, The wires 24, 25,

ends are each :provided with the air choke coils 11, whichin turn are 'conneCtedin-Sefies with the telegraph keys or instruments indicated at 12.

In Figure 4, I illustrate a single telegraph wire 10 for quadruplex or duplex service; the'high frequency apparatus bridge being represented at 18, which are bridged between the line and ,ground at both ends ofthe line, a shown at 30. The ends ,of'thejline are also provided with air choke coils 11, in series with the telegraph keys or instruments 12.

Figure 5 diagrammatically illustrates two both tel-egraph or both telephone wires; the

figure showing more than one set onthesame line, as for example 18 designates the high frequency transmitter of one circuit; 18 .in-V

dicating the high frequency receiver at the distant end of the circuit; while 18 is the high frequency transmitter of another circuit-and 18 is the high frequency receiver at the distant end of the last mentioned -circuit. It is, of course, apparent that any -desired number of sets (as shown) maybe in,- volved that they would be "connected vto the line wires in similar manner and that there would be no interference between the different multiplex circuits; the circuits comprisingjair choke coils llarrangedin series with the telegraph keys or instruments indicated at .12. I

In order to accomplish the various objects and advantages heretofore .set forth, use is made of oscillationsor electromagnetic waves offhigh frequency whichraretransmitted. over 7 the wires; the frequencies in tests that have been made, being above audibilitv;

telephoneline as one side volf a pair of my .cir-

ies In practice, Ihave made use of a metallic cuit, by shunting the metallic telephone line with a number of small capacity condensers,

:as for example two, arranged in series and? connecting the centers of the condensers di rent to :a telegraph :Wire, and using a telegraph wire as the other side of the pair of lines of the :circuit; Figure 1 illustrating the multiplex apparatus bridged-acrossartelegraph wire and ametallicitelephone circuit.

' .In a test made over a circuit of a considerable distance, one side of the circuitconsisted offNumber 9. copper wire in quadrnplex service, whilethe other side of'the circuit was a, single ,lMorse Number 9 copper wire and a metallic vdispatcherls telephone line a of .Nuinber 9 copper wire, with connectionsrarranged as shown .in Figure 2. The reception over these imixedtelephone telegraph Wires was withoutinterference either 'to the ,multi-' plex circuitpr to the circuits "being worked v .over, and ireeeption was equivalent .to ten standard transmission units; c r wellrknownedtil asibee possible to aio ' reception was Without interruption when the receiver,.caused by leakage between the two telegraph wires and electro-magnetic and electro-static disturbances from adjacent wires; the disturbances'in the receiver being much greater if the two telegraph wires are spaced farther apart on the pole lines. On the other hand, in tests with my apparatus,

set was connected either between adjacent wires on the same arm or between a wire on one arm and a wire on another arm. If more than one circuit is to be'connected to the same line wires, the connections for the apparatus of different circuits may be to the same point on the line. 7

The modulated high frequency current is impressed on the lines which are connected as shown in Figures 1, 2, 8, 4 and 5, which illustrate the different combinations of untransposed wires with which connection is made and the use of air choke coils and condensers, by means of which the modulated high frequency currents are conducted over the wires without interfering with existing circuits.

Referring to Figure 3, 24is a wire in quadruplex service connected to the wire 25 by the small condenser 28. This forms one side of a circuit for multiplex operation.

Wires 26 and 27 are also connected by a small condenser 29 and form the other side i of the multiplex circuit.v The quadruplex no apparent loss of transmission and disturbing noises cannot be he'ard in the metallic telephone line, since the condensers are balanced to either line wire by reason of the center connection as shown. From the con- 7 densers 15 at the left, a connection is made to single Morse wire21 which has nointermediate stations cut in/it. The telegraph instruments shown at 12 at either end of the single Morse wire have the air choke coils 11 inserted in series with the line wire to prevent disturbances from telegraph operation in the multiplex circuit. 10 is a quadruplex line with the usual instruments connected at 12 in series with the air choke coils 11. The

multiplex apparatus is bridged at 6667 on the telegraph ends and at 6869 on the telephone, telegraph ends of the circuit; choke coils and condensers being used likewise in Figures 1, 4 and 5.

I have shown various methods of arranging the circuits involving my invention; it being understood, however, that variations or modifications may be made without, however, departing from the spirit of my invention; the invention having been described in terms employed merely as terms of description and not as terms of limitation.

What I claim is: s

1. Telephone and telegraph circuits comprising sending and receiving telephone and telegraph apparatus, line circuits, a super imposed circuit on said line circuits involving additional sending and receiving apparatus, air choke coils connected in series between the first mentioned telegraph sending and receivingapparatus and the ends of the telegraph portion of the line circuits, and small capacity condensers connected in series across the line wires of the telephone portion of said line circuits so as to provide a connection for the super-imposed circuit to the telephone portion of the circuits of equal capacity to both sides of said line wires of the telephone portion of the line circuits.

2. Telephone and telegraph circuits comprising sending and receiving a paratus, line circuits, a superimposed high fiiequency circuit on said line circuits involving additional sending and receiving apparatus, air choke coils connected in series between the first mentioned telegraph sending and receiving apparatus and the ends of the telegraph portion of the line circuits, and small capacity condensers connected in series between the line wires of said line circuits so as to provide a connection for the superimposed circuit.

JOHN W. COOK. 

